Opposition Leader Anthony Albanese is digging in behind MP Anthony Byrne, who has admitted to using taxpayer-funded staff to help with branch stacking in Victoria, but others in Labor believe Mr Byrne’s tenure is politically unsustainable.

Mr Byrne, who appeared this week as a witness in the branch-stacking inquiry by Victoria’s Independent Broad-based Anti-corruption Commission (IBAC), is also deputy chairman of the Parliamentary Joint Committee on Intelligence and Security.